A Line Mechanic working ATR aircraft described the conflicting demands of trying to satisfy Engineering Orders (E/Os); Emergency Equipment list changes; lack of adequate inventory; completing Overnight Maintenance Checks and still meet departure schedules.

Narrative

Having been assigned an ATR aircraft Periodic Service (PS) Overnight Service Check with an Engine One (E-1) Starter/Generator Remove/Replace (R/R) and installation of demo/equipment bag due last night; I again notified both the Lead Mechanic and Supervisor of the continued improbability of compliance with the Engineering Order (EO) # XXX-181. I was told to go do it. There are no demo life vests in the system although the Part Number (P/N) does pull up in Inventory. Also there has not been; on any ATR; any demo life vest on the aircraft as the flight attendants keep them for themselves in their flight bags. After initially going Aircraft On Ground (AOG) for the correct P/N; having partially complied with EO# XXX-181; and thus grounding the aircraft; the Supervisor sarcastically challenged my professionalism and stated that if he was going to take a hit for the Out of Service aircraft in the morning; I would take a hit for it. I also brought out the point that the current Emergency Equipment List (EEL) shows the cabin configured with the demo bag installed. I left the five O2 masks required by the EEL under both flight attendant seats alone; and then forgot about it.I have done several PS Checks on other ATR's in the last few weeks and have not addressed or corrected the aircraft to comply with the new EEL's onboard. No one else has either. I felt my job/work security had been obviously threatened; and made the decision to not comply with the EO and return the aircraft to original configuration. In regards to leaving alone the passenger O2 mask issue; I was too focused on finding a solution for demo equipment and did not want to antagonize the Supervisor any more. I got no help from the Supervisor or the Lead mechanics; and felt left swinging in the breeze yet again. The EO; Fleet Directives (F/D) and EEL's are not in coordination with each other; making an unsustainable conflict; even the picture in the EO is admittedly incorrect and does not address the different bin configurations between the aircraft. There needs to be thorough coordination between companies numerous maintenance documentations. The technicians must be made sure that making the correct ethical decisions will be supported by Management without any kind of threat of retaliation or punishment. Compliance dates would be very helpful as well. Having all needed parts with their respective P/Ns fully listed on the list of materials should be mandatory.